This photo made available by NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington on Tuesday, Nov. 27, 2012 shows a 68-mile-diameter crater, large indentation at center, in the north polar region of Mercury which has been shown to harbor water ice, thanks to measurements by the Messenger spacecraft. (NASA)

CAPE CANAVERAL, Fla. — A NASA spacecraft carrying a University of Colorado-built instrument has confirmed there's ice at Mercury's north pole.

Scientists announced today that the orbiting probe, Messenger, has found evidence of frozen water, even though Mercury is the closest planet to the sun.

The ice is located in the permanently shadowed region of Mercury's north pole. It's thought to be at least one-and-a-half feet deep — and possibly as much as 65 feet deep.

Scientists say it's likely Mercury's south pole also has ice, though there are no data to support it. Messenger orbits much closer to the north pole than the south.

Radar measurements, for years, have suggested the presence of ice. Now scientists know for a fact.

Messenger is the first spacecraft to orbit Mercury. It was launched in 2004.

The spacecraft is carrying the Mercury Atmospheric and Surface Composition Spectrometer, or MASCS, which was designed and built at CU's Laboratory for Atmospheric and Space Physics.

MASCS is designed to measure the spectrum of light reflecting off Mercury's surface. Because different minerals absorb different wavelengths, scientists can compare the reflected light to light directly from the sun, calculate which wavelengths are missing and determine what kinds of minerals make up Mercury's surface.

CU officials said the MASCS instrument was not involved in the discovery of ice on Mercury.